This application is for funds to conduct a workshop conference on intense light effects in clinical practice, with particular emphasis on hazards to the retinas of normal and dystrophic eyes from diagnostic and treatment devices. A number of devices are in use today for diagnosis and treatment which present potential hazards to normal retinas because they are thought to exceed present safety guidelines. There is evidence from experiments on animals that lower intensities than those which have been declared hazardous, when presented repeatedly, produce prolonged or irreversible functional changes and/or subtle pathology. There is a widely expressed concern about the deleterious effects of light exposure to eyes suffering from degenerative retinal disorders. Also, there is the possibility, based on some evidence from animal studies, of beneficial effects of protecting those eyes from every-day light exposure. Yet, there is no primarily health-directed program for organized research in these areas. The proposed conference will bring together clinicians and basic scientists whose work touches these questions. Out of this conference should grow an appreciation of the state of knowledge on intense light effects and the retina, a better understanding of the areas which need further research, and the beginnings of a plan for implementing those research objectives.